1. Field of the Invention
This invention relates a photographic camera provided with a cartridge chamber in which a film cartridge is loaded.
2. Description of the Related Art
Recently there has been proposed a film cartridge having a film exit slit and a light-shielding shutter member for opening and closing the film exit slit. In such a film cartridge, when the film exit slit is closed by the shutter member, the roll film is entirely rolled around a spool to its leading end and held in a light-tight fashion and the roll film is fed out of the cartridge body and rewound into the cartridge body with the film exit slit opened. See, for instance, U.S. Pat. No. 5,025,274.
Further there have proposed various photographic cameras which use such a film cartridge. Generally such a photographic camera is provided with a cartridge chamber in which the film cartridge is loaded, a chamber lid which opens and closes an entrance opening to the cartridge chamber, a lock lever which is moved to a locking position in response to closure of the chamber lid to lock the chamber lid in the closed position and is moved to an unlocking position to release the chamber lid in response to an operation for opening the chamber lid, a spool drive member which is engaged with the spool of the film cartridge loaded in the cartridge chamber and is driven in the regular direction or the reverse direction by a motor to rotate the spool to feed out and rewind the film from and into the cartridge body, and a shutter member opening/closing member which is engaged with the light-shielding shutter member of the film cartridge and opens and closes the film exit slit. The film cartridge loaded in the cartridge chamber is in engagement with only the spool drive member and the cartridge body is floated in the cartridge chamber.
When film cartridge is to be taken out from the cartridge chamber, the light-shielding shutter member must be disengaged from the shutter member opening/closing member. For this purpose, the cartridge chamber is provided with a lifter member which disengages the shutter member from the opening/closing member and facilitates taking out the film cartridge. The lifter member is urged toward the entrance opening to the cartridge chamber by a spring and is pushed away from the initial position overcoming the force of the spring by the leading end face of the film cartridge when the film cartridge is inserted into the cartridge chamber. The lifter member is moved to a retracted position away from the film cartridge in response to closure of the chamber lid, thereby causing the film cartridge to float in the cartridge chamber. When the chamber lid is opened, the lifter member is moved toward the entrance opening under the force of the spring and pushes the film cartridge toward the entrance opening, thereby disengaging the shutter member from the opening/closing member and ejecting the film cartridge from the cartridge chamber.
Further, there has been known a photographic camera using a film cartridge which is provided with first and second lifter members. In such a camera, the first and second lifter member are spring-urged toward the entrance opening to the cartridge chamber and are respectively brought into abutment against the chamber lid and the film cartridge loaded in the cartridge chamber. When there is no film cartridge loaded in the cartridge chamber, only the first lifter member is moved toward the entrance opening and when a film cartridge is loaded in the cartridge chamber, the first lifter member moves the second lifter member to a retracted position away from the film cartridge in response to closure of the chamber lid. When the chamber lid is opened, the second lifter member is moved toward the entrance opening under the force of the spring and pushes the film cartridge toward the entrance opening, thereby disengaging the shutter member from the opening/closing member.
In order to disengage the shutter member from the opening/closing member and eject the film cartridge from the cartridge chamber, it is necessary that the force of the spring urging the lifter member toward the entrance opening is relatively strong, e.g., about 300 g. However when a spring having a large force is used, the lifter and the spring mounting structure of the camera body must be arranged to withstand the large spring force, which adds to the sizes of these parts and the overall size of the camera. Further, the spring which urges the lifter member, especially the springs which respectively urge the first and second lifter members, adds to the number of components of the camera, thereby adding to the manufacturing cost of the camera.